ACC/AHA/ESC guidelines recommend sublingual nitroglycerin (SNG) in patients with stable angina pectoris and coronary artery disease (CAD). However, the shelf life of SNG following first use is six months for SNG tablets and two years for SNG sprays. We investigated the frequency of prescription of SNG tablets/sprays in patients having anginal symptoms and documented CAD and the awareness levels of patients about appropriate use of SNG.
Three hundred patients (201 men, 99 women; mean age 61.7±10.8 years) with documented CAD and angina were enrolled into this study. Angina pectoris was categorized according to the functional classification system of the Canadian Cardiovascular Society. Data on cardiovascular past histories, risk factors, medications, and the use of SNG were recorded.
At least one risk factor was present in 96% of the patients. Only 46% of the patients had a prescription for SNG. Of those with a prescription of SNG tablet and spray, 91.8% and 84.4% did not know the shelf life of the product, respectively. Of those who were routinely carrying SNG, 35.6% had an expired product. Of those with a prescription of SNG, only 65.9% were informed by the physician on the proper use of SNG.
Our results show that, despite recommendations of the guidelines, SNG is not prescribed to a substantial percentage of patients with CAD and angina, a considerable fraction of patients carry an expired product, and that patients are not adequately informed by the physicians on the use of SNG. These problems will certainly affect the optimal medical management of CAD and its efficacy.